Process of melting varnish-gums.



UNITED STATES PATENT 'oFFIoE.

MICHIGAN, A COBPORATION OF MICHIGAN.

rnoonssor MELTING VARNISI-I-GUMS.

No Drawing.

739 all whom it may concern:

Be it known that I, OTTO C. GRIEM, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful. Improvements in Processes of Melting Varnish-Gums, of which the following is a specification.

The invention relates to the manufacture of varnish and it is the object of the invention, first, to avoid' discoloration of the.

gum in melting; and second, to facilitate the melting and to shorten the time required for the same.

In the'present state of the art it is usual to place the various gums, resins and similar vegetable secretions from which the varnish subjected to a temperature ranging from 220 to 650 F. It has been found that during this melting the gums are frequently discolored to a greater or less extent, whic is detrimental. I have discovered that by parboiling the gums in water and then pouring off the Water and melting, discoloration is prevented and the whole process can be carried out in less time The reason for this improved result is not fully understood but may possibly be accounted for, first, by the elimination from the gum during the parboiling of certain ingredients which would cause discoloration if raised to a high temperature. Another possible explanation is the fact that the gum, which originally is in chunks, will when placed in the kettle be incontact with air in the spaces between'the particles. Thus the particles which are at the bottom of the kettle and are first melted will be in Contact with air at relatively high temperature, causing oxidation or other Specification of Letters Patent. Patented May 7, 1918. Application filed November 17, 1917. Serial No. 202,558.

chemical change, producing discoloration. When, however, the gum is first heated While covered With water or other medium forexcludin' the air the particles will be plastic "one o. GBIEM, or DETROIT, MICHIGAN, ASSIGNOR T0 sunny BROTHERS, or DETROIT,

and Will flow together so as to exclude the air after the water. is poured 01f. Whatever the action may be, the effect produced is to melt the gum more readily and without objectionable discoloration.

In the specific application of my process 'thegums are first covered with water and 1 parboiled for approximately one-half hour. The water is then poured 0E and the melting is effected in approximately 2% to 2:}- hours, the temperature ranging from 220 to 600 01' 650 F.

What I claim as my lnvention is:

1. The process of melting gums, comprising the protectin of the particles from air contact and whi e so protected fusing the same together.

'2. The process of.1nelting,gums, c0mp1iS ing the filling of the spaces between the particles of gum With a medium for excluding air, fusing the particles together and con.- tinuing the heat treatment until completely melted.

3. The process of melting gums, comprising the covering of the gum 'With a non-solvent liquid, heating until theparticles are fused together, pouring off the liquid and continuing the heating until completely melted.

- 4. The process of melt ng gums, comprising the covering of theparticles with water, boiling until the particles are softened. 

